Edward Snowden's criticism of Hillary Clinton's plan to fight encrypted companies is fair, since it relates to privacy in communication. Maintaining law and order and protection and security of people cannot be assured even through surveillance systems. Such surveillance systems might even be unable to control the rapid growth of hackers.
Hilary Clinton's position on encrypted companies is hypocritical at the least. She was the one who had her own server for her emails. And for Snowden to criticize her was perfectly sensible. Encryption is a necessary part of any company. Without it, no one would trust putting their information anywhere on the Internet. Even with the current levels of encryption, websites get hacked and information gets leaked all the time. It is ridiculous to promote less encryption by companies. Although, giving her the benefit of the doubt, I doubt she meant that all companies should ban encryption. If anything, she was echoing sentiments that tech companies and law enforcement should work together to take down groups like ISIS, who use encryption for malicious purposes.
Snowden's evaluation of Hilary Clinton is fair because it is true that it is her own fault that her emails were leaked, and even more so her fault because she should have known better then to transmit classified information over her own server. She is at fault for her own poor handling of the situation and therefore criticism is founded.
Hillary Clinton is running for president. Of course it's fair to criticize her or her policies. Edward Snowden is allowed to criticize if he feels fit. He may not be well liked, but he is still entitled to his opinion. It's our responsibility whether or not to believe what he says.